Our series “How I became a …” digs into the stories of accomplished and influential people, finding out how they got to where they are in their careers.

Editor’s note: This interview has been edited for brevity and clarity.

Scott Harrison was in his late twenties, living and partying in New York City as a nightclub promoter when he came to the halting realization that he was creating “perhaps the most meaningless legacy a person could leave.” He sold his things, packed his bags, and moved to Liberia on a humanitarian mission, discovering a world in which people drank from muddy swamps and hiked miles for a drop of water. His mission became charity: water, a non-profit organization that has since brought clean water to millions of people in developing countries.

USA TODAY caught up with Harrison — whose book “Thirst: A Story of Redemption, Compassion, and a Mission to Bring Clean Water to the World” went out on bookstore shelves Oct. 2 — to talk about everything from world travel and nightclub promotion to the awe of hearing President Obama tell his story and the painful low of realizing the turmoil that dirty water can cause in a village.

Question: What is your coffee order?

Harrison: Cappuccino.

Q: What is the last book you read?

Harrison: The last book I just finished was called “A Character of Virtue: Letters to a Godson.” I was just recently made a godfather and decided to do some reading and take it seriously. I thought it was great. It is about a godfather who tries to teach virtues to his godson – a different virtue every year of his life.

This is the cover of Scott Harrison’s new book, “Thirst.” Harrison is the founder and CEO of charity: water.(Photo: charity:water, )

Q: Who has been your biggest mentor?

Harrison: This guy named Ross Garber. I worked with him for maybe four or five years – he was the founder of an internet startup in Austin called Vignette – scaled very quickly, zero to 2,000 employees in a few years or something like that – he did very well. Our relationship started with him as a disgruntled customer. He had donated his birthday (proceeds) to charity: water, and he thought our web product experience was so bad that he wrote a 10-point scathing email to his friend, who then forwarded it on to me. I’m like “this is amazing.” I crave negative feedback. So, I wrote him and said "hey, can we get on the phone? I think I actually agree with eight of your 10 points, but I’d love to hear a little more." It developed into a really constructive, dynamic relationship. At the end of the year, he would send me a bill for a million dollars, with a zero balance – he just wanted me to always know how much he thought his services were worth, but he never made me pay.

Harrison: I’ve traveled to Ethiopia 30 times, and I’ve fallen in love with the country of Ethiopia. Besides being able to help 2 million people get clean drinking water there, to have been able to have some unbelievable cultural experiences there. Climbing up cliffs to meet 100-year-old priests who are living in rock churches. Just being able to trek. It’s really my favorite place.

Scott Harrison is the founder and CEO of charity:water an non-profit that works to bring clear water to locations around the world that need it.(Photo: charity:water, )

Q: What are some of your go-to songs and podcasts?

I used to write to and edit photos all the time to William Orbit’s version of Adagio for Strings. I would just play it on repeat and it would run for hours in the background.

I love Yo-Yo Ma.

I’m a fan of Masters of Scale right now, Reid Hoffman’s podcast.

Q: What does your career path look like?

Harrison: Not traditional. I started out as a club promoter in New York City, which was really an act of rebellion against a conservative Christian upbringing, helping to take care of a mom who was an invalid while I was growing up. I spent 10 years really getting drunk, getting other people drunk, working at 40 different nightclubs, and picking up every vice that you might imagine would come with the territory – so, smoking, heavy drinking, heavy gambling, problems with pornography and drug use. At 28, you know, I came to the realization that I was spiritually bankrupt, I was morally bankrupt, I was leaving perhaps the most meaningless legacy a person could leave. Who wanted to live their life and just get millions of people wasted? That realization led me to trying to find my way back to a lost faith and spirituality, trying to find my way back to virtue and morality. I sold almost everything I owned, all of my earthly possessions, and asked myself: what would the exact opposite of my life look like? The only thing I could think of was to go serve the poor in the poorest country in the world, give one of the 10 years that I had so selfishly wasted back in service to others and to quit all of my vices – quit drinking and drugging and smoking and gambling, and all of the rest.

That led me on a humanitarian mission as a photojournalist to Liberia, a country that just emerged from a 14-year civil war led by Charles Taylor and his army of children. I joined a medical mission and saw extreme poverty for the first time. One year turned into two years, and the thing that struck me the most — the one thing that just wasn’t okay on my watch — was that people were drinking dirty water. I had never seen human beings drink from brown, viscous swamps or ponds or rivers before. I had never seen or heard of children dying from diarrhea or dehydration or some of these other water-borne diseases. I think it was in stark contrast to my former life, where I sold bottles of water at nightclubs for $10. That led me to really want to work on water, and want to bring clean drinking water to everyone alive, and then that led me to charity: water.

Q: What does a typical day look like for you now?

Harrison: There’s a day on the road – I make about 150 speeches a year, so 60 flights or so. So, a day on the road would be: up early, breakfast with a donor, one/maybe two/maybe even three talks or lectures that day, maybe an evening dinner again with a supporter in that city, maybe a little news before bed.

At home, it’s waking up, fixing breakfast for my kids – eggs, avocado toast, bagels with cream cheese – then walking my four-year-old to preschool, hitting the office for a bunch of internal meetings first, and then often hosting again out-of-town supporters or donors in the office: giving them a tour, sitting with them, thanking them for their generosity. Home by six to have dinner with the kids and play board games and put them to bed.

I am about to do nine cities [on book tour] and I’m going to bring my four-year-old to Atlanta. I’m going to put him in a 7,000 person audience, and then in a 20,000 person audience in Boston, so he’s going to come with me on some of these. I can’t wait. I started him flying early – he did 20 flights his first year of life, so I wanted him to get used to airplanes. I had him in Sacramento recently in a big audience, and I said “okay, so Daddy’s going to talk for about 30 minutes on stage, so just sit and be really quiet. Just sit for 30 minutes.” He was sitting with a friend. About 10 minutes into the speech, I hear “daddy!” just yelling “daddy!” from the middle of the audience.

Scott Harrison is the founder and CEO of a nonprofit called charity:water.(Photo: charity:water, )

Q: What is the biggest lesson you’ve learned?

Harrison: Put integrity at the core of everything you do. I think so much more important than what you do is how you do it. It’s a core value important to me in my life, and [a] core value of charity: water.

Q: Do you remember a pivotal moment in which you realized that this was what you were meant to do?

Harrison: I think it was really day one of charity: water, when the whole thing came together. I threw a party, invited 700 people to come to my 31st birthday party, and asked them all to donate $20 on the way in. We raised $15,000 that night, and we took 100 percent of the money to a refugee camp in northern Uganda where 31,638 people were living, drinking unsafe water. We built our first water project, and then we sent the photos and the GPS coordinates and the water flowing back to those 700 people, and the response that I got just let me know that I was really on the right path. People were just so surprised that a charity would bother to tell them where $20 went, and that something transformative had happened along the way, and they said “this is amazing. How do we continue to give? How do we do more?”

Q: What has been your biggest career high, and your biggest career low?

High: I was invited to the National Prayer Breakfast with my wife and I was sitting there at one of the tables, paying attention as President Obama was giving his speech. Then, in the middle of his speech, he starts telling my story – he starts saying “there’s this guy named Scott Harrison, he used to be a nightclub promoter, and he wasn’t serving God, and he was a mess, and then he started this charity, and he’s bringing clean water to people and he wants to help a hundred million people, and this is the kind of faith that we need in this country, and people that are living out a vision of unselfishness,” and I just couldn’t believe it. I had actually never met President Obama, and here he is, spending minutes of his speech telling my story. My wife gripped my hand like she was going to break it, and it was a really humbling moment, to hear him talking about my life and about charity: water in such an honoring way.

Scott Harrison, the founder and CEO of charity: water, interacts with residents of a village in Liberia.(Photo: charity:water, )

Low: Living in a village in Ethiopia where a 13-year-old girl hung herself after she had spilled her water. She had been walking eight hours a day with a clay pot on her back, and one day after a long journey she slipped and fell, and she broke her pot and she watched all of the water that she had spent a day walking for just spill out into the sand, and she just didn’t want to go walk for water anymore. She took a noose and tied it around her neck and she climbed a tree and she jumped. The village elders found this 13-year-old girl’s body swinging from a tree, and I lived in this village for a week. I met her mom, and her family, and I went to her grave and I walked in her footsteps, and then I stood next to the tree, which for me was just this really shocking moment of just realizing the injustice, the travesty, the fact that just because this little girl was born into a village where there was no clean water – because she was one of 663 million. 13-year-old girls should not be hanging from trees. It really re-energized me with a deeper passion and a need to go faster, to help more people, to make sure that no woman, no child, no 13-year-old girl is walking eight hours for dirty water.

Q: What advice would you give to someone who wants to follow in your footsteps?

Harrison: I would say to go deep. Go deep with whatever issue they really want to make an impact in. So many people have such a cursory knowledge of an issue, or maybe a problem in the world, and for me, living in West Africa, walking through hundreds and hundreds and hundreds of villages without clean water gave me such a deeper understanding of the needs and the solutions and of the transformation that clean water brings to people and to communities. I would encourage people to find the thing that really speaks to them: what is that thing that is not okay? That injustice – maybe it’s a hunger issue, maybe it is clean water, maybe it’s the fact that people are going to bed without a roof over their heads, maybe it’s a justice issue. Find that one thing that they can be passionate about for a long time and then go deep, and immerse themselves in understanding the problem and then the solutions.